1. Field of the Invention
This invention relates to a passive seatbelt driving mechanism for a passive seatbelt system for automatically fastening a seatbelt to an occupant after he gets on the vehicle.
2. Description of the Prior Art
In spite of the fact that high level of safety is attained by seatbelt systems in an emergency of a vehicle, the rate of seatbelt utilization is very low because of troublesome fastening process or the like. Hence, there have been proposed various types of seatbelt systems capable of automatically fastening a retaining webbing to an occupant after he gets on the vehicle. Among those various seatbelt systems, there is a passive seatbelt system constructed such that the force for opening or closing the door for getting on or off is utilized when the door is opened or closed to bring the intermediate portion of the webbing into contact with or separate same from the occupant's seat without requiring any special driving force and which is highly evaluated from the viewpoints of reliability and economy.
However, in said passive seatbelt system, the interval formed between the intermediate portion of the webbing and the occupant's seat is proportional to the value of the door opening, and hence, such a disadvantage is presented that, when the door is not fully opened, positive and sufficient space for getting on or off can not necessarily be obtained.